This invention pertains to vane pumps and, more particularly, to such a pump wherein additional filling passages are provided in the rotor to fill the spaces between vanes whereby the spaces are filled even when the pump operates at a relatively high rotational speed.
In prior art vane pumps operating at high rotational speeds, there has been an inability to completely fill the spaces between successive vanes in the intake area. Efforts to solve this problem in the past have included the use of means, such as additional pumping mechanism, to provide high fluid inlet pressure to the fluid being supplied to said intake area. Another alternative has been to provide an opening in the cam ring surrounding the rotor and which controls the movement of the vanes. However, this has increased the contact stress between a vane tip and the surface of the cam ring. The foregoing expedients have resulted in either substantially increased costs in achieving the result or the pumps have not operated efficiently with a long useful life.